Finally, Clive Palmer has formally put a full stop to his personal political career, announcing on Monday he won’t be running for the Senate.

Palmer United Party (PUP) will still field Senate candidates, including its sole senator, Dio Wang. But if he or any other PUP candidate fluked a Senate seat, it would surely be unlikely Palmer would have influence with them.

The bizarre Palmer experiment appears to be well and truly over. The former member for Fairfax spent a fortune to win a slice of national political power, and then spectacularly lost that power. He won’t be missed. The Palmer story has morphed into one about the financial havoc he has wrought.

But the PUP vote, especially in the vital state of Queensland where in 2013 the new party polled some 11% of the House of Representatives vote and nearly 10% in the Senate (winning a Senate seat), will be keenly sought. ABC electoral analyst Antony Green says in 2013 PUP garnered votes from Labor and from the Greens in Queensland but “there is not research on who the Palmer voters were” and on July 2 this vote “will be up for grabs”.

Where the vote will go now PUP is discredited is one of many uncertainties at the start of the campaign’s third week.

Saturday’s Fairfax Ipsos poll (51-49% in the Coalition’s favour) and Monday’s Newspoll (49-51% against the Coalition) show a neck-and-neck race in the broad polls. When they toppled Tony Abbott in September Liberal MPs probably expected they would be a good deal better placed now than represented by these figures.

A couple of things may be going on here.

Government strategists suggest the national polls mask a rather different back story. The Coalition is doing better in the marginal seats, they say, where its economic message is getting across well. It’s the marginals in which elections are won and lost and what’s happening there is of prime concern to the parties.

The Liberals may be “spinning” or telling the truth – it is hard to know. Public polling done in marginals is usually very hit and miss when tested against the later outcomes.

But worrying for the Coalition, based on Malcolm Turnbull’s tumbling personal ratings in recent months, is that the Liberals may have miscalculated what would be Turnbull’s electoral appeal when they installed him in September.

It wouldn’t be the first time that a party over-estimated what a leadership change would bring in terms of votes. Polling analyst John Stirton says “leaders tend to be more popular in exile than in office”, citing the Andrew Peacock/John Howard opposition experience through the 1980s.

In 1989 the Liberals dumped Howard for Peacock, looking for an electoral transformation. Peacock performed less well than they hoped and could not match Bob Hawke at the 1990 election.

In 2010 Labor had a panic attack, fuelled by frustration with Kevin Rudd’s style, and dumped him for Julia Gillard who, in part because she was undermined by Rudd, ended up in minority government after that year’s election.

And before that, in 2008, the Liberals had been persuaded by Turnbull’s high popularity ratings, so much better than those of then-opposition leader Brendan Nelson, only to see those figures fall after he became leader.

A number of factors can be identified as to why Turnbull currently is not fulfilling what his backers saw as his promise.

He’s had to, or has chosen to, compromise on the policy positions with which he was identified. He has lived with Tony Abbott’s “direct action” on climate and same-sex marriage plebiscite.

It has confused some voters who want to get a fix on him and what he stands for, and alienated others who were convinced they had that fix and now find he’s not just slid away but embraced some positions – such as a hard line on people on Nauru and Manus Island – that they thought he would eschew.

“I want the old Malcolm back,” lamented a questioner on the ABC’s Q&A on Monday night.

This is part of a wider phenomenon of disappointed expectations. People anticipated Turnbull would deliver a lot more. Some of the expectations arose just because he was Turnbull, with all the hype that brought.

In other cases, for example on tax reform, he raised the prospect of big things and then stepped back. A man whom some saw as rather extraordinary – in a good way – came to look dishearteningly ordinary.

Turnbull’s style, so attractive to aficionados, may also be less suited to a campaign in these times than the more down-to-earth approach of Bill Shorten. Turnbull often talks in grandiose terms; Shorten, with his mantras about education and health, may be closer to people’s immediate concerns. Shorten appears at home on the campaign trial; Turnbull, less so. The suburban shopping centres don’t look like Turnbull’s natural habitat.

And a campaign helps elevate an opposition leader, especially if he is performing competently.

So as Turnbull’s net approval has fallen and Shorten’s has risen, they have come to the point where they have a shared distinction – they are equally disapproved of. Each has a net satisfaction rating of minus 12.

Even though he may look the less comfortable campaigner, Turnbull retains a substantial advantage in this long race. He is defending a mountain of seats while Shorten has the considerably harder task of wresting them away. In addition he has a large, albeit eroding, margin as preferred prime minister.

And for Liberals who might be looking rather bleakly at those national polls, they can always contemplate where they’d be if it were Abbott confronting Shorten.